This invention relates to a disc cartridge, and more particularly to a disc cartridge which has a hard disc, particularly, a double-sided type hard disc housed in a casing.
In general, a disc-type data recording carrier such as a compact disc (CD), a video disc (LD) or the like is used in a manner to be removed from a packing case and set in recording and/or reproducing equipment.
Conventionally, it has been desirable to protect such a disc type recording carrier from environment because it is not only readily covered with dust and damaged but adversely affected due to a variation in temperature. For this purpose, the use of an envelope such as a tray, a casing or the like has been proposed to protect the disc. Unfortunately, such a conventional envelope is not suitable for the protection of a double-sided hard disc, because the housing of the disc in a storage space defined in the envelope causes the disc to be contacted with the envelope. Also, the envelope causes the disc to be contacted with an inner surface thereof during the storage or transportation. Thus, the use of the envelope results in damage and/or pollution of the disc as well as the exposure of the disc to a variation in temperature. Further, when a shutter provided at the conventional envelope to operate a window for inserting a disc driving mechanism of a disc player such as a recording and/or reproducing head therethrough into the disc cartridge is increased in length, any deformation of the shutter such as the outward expansion or the like readily occurs at the shutter during the processing. In order to avoid such a disadvantage, it is proposed to reinforce the shutter by bonding a specific part thereto by ultrasonic sealing or the like. Unfortunately, this fails to provide the envelope with high dimensional accuracy and renders the manufacturing cost significantly high. Also, this has another disadvantage of causing the handling of the disc cartridge to be highly troublesome.
Accordingly, it would be highly desirable to provide a disc cartridge which is capable of keeping a shutter at a correct posture and preventing any deformation of the shutter to ensure the smooth operation of the disc cartridge and the safe housing of a disc in a casing.